The invention relates generally to a steering wheel having a hub, spokes, a steering wheel rim, and an airbag module.
Steering wheels of motor vehicles are generally fitted with an airbag for the protection of the occupant in the event of a crash. The airbag is thereby mounted rigid or movable in an airbag module in the center of the steering wheel relative to the longitudinal axis of the steering column. This driver airbag has a symmetrical shape in the inflated state so that it is active in the same way irrespective of the rotary position of the steering wheel.
The drawback with the known driver airbag is that the symmetrical shape does not offer optimum protection for the occupant. An asymmetric shape could indeed improve the protection when the steering wheel is in a certain position, e.g. when set up straight. In other positions of the steering wheel, an asymmetrical position would impair protection compared with a symmetrical airbag.
A further drawback is that the airbag unfolds inclined upwards in the event of a crash depending on the angle of the steering column. The airbag thereby does not act with its entire surface area evenly on the body of the occupant but certain areas of the body suffer greater impact. To avoid this disadvantage it is known from DE 196 07 193 A1 to tilt the steering wheel downwards. The steering wheel is thereby fixed for articulated movement in the upper area of the hub and in the event of a crash can be turned away downwards through a pyrotechnic device. The plane of the steering wheel rim is thereby set approximately parallel to the body of the occupant. The airbag then unfolds in a direction which is approximately the horizontal direction and the airbag forces act more uniformly on the driver. At the same time the risk of injury through the lower area of the steering wheel rim is also reduced.
The drawback with this tilting steering wheel is that a pyrotechnic device with associated electronics is required to tilt the steering wheel in the event of a crash.
The object of the invention is to change the steering wheel so that improved protection of the occupant is possible independently of the position of the steering wheel and without the expense of extra measures.